1. Field of the Invention
The present invention relates to a modular prosthetic conduit implantable within a mammal and a method of surgically implanting and replacing such a conduit. Specifically, the present invention is directed toward a conduit comprising a first conduit member composed of a nonporous biocompatible alloplast--such as silicone rubber and coated on its exterior surface with a porous biocompatible tissue-bonding material. The present invention is further directed toward a second conduit member composed of a nonporous biocompatible alloplast, such as silicone rubber. The second conduit member contains a region or component that can be expanded radially by mechanical, hydraulic, chemical, electrical, temperaturesensitive or other physical means. This component of the second conduit member may be temperature-sensitive region or component such that at low temperatures, it can be easily slid into or out of the first conduit member, and at temperatures approaching a mammal's body temperature, the temperature sensitive region expands to form a watertight "docking" fit within the first conduit member. The second conduit member may also contain remotely actuable valve and pump.
2. Description of the Prior Art
Implantable prosthetic conduits are frequently used in the field of medicine to provide pathways for transporting fluids or energy. Such conduits may also have other applications, such as the inclusion of reservoirs in the medical sciences. A common problem encountered with medical implants is infection. Proper bonding between the implant and the tissue in which it is implanted is an important factor in avoiding infection.
It is known that biocompatible alloplastic devices coated with porous biocompatible tissue-bonding material, such as porous polytetrafluoroethylene (PTFE), or porous polyurethane, or porous Dacron.RTM. (polyethylene terephthalate fiber) or other porous biocompatible alloplasts, effectively bond with epithelial-lined muscular visceral tissues in watertight anastomotic union. Long-term durability of such anastomoses has been achieved in both humans and in animals. Extraluminal porous biocompatible tissue-bonding material, such as polytetrafluoroethylene or porous Dacron.RTM. or porous polyurethane or other porous biocompatible alloplasts, in such unions does not usually become colonized with intraluminal bacteria.
Bacterial colonization of porous biocompatible tissue-bonding material is common with porous devices that pass transcutaneously or into body viscera, such as the urinary collecting system. Such colonization leads to the erosion of the anastomoses and loss of any implanted conduit or related prosthetic device.
Nonporous biocompatible alloplast tubes that pass through viscera, such as the epithelial-lined muscular organs, including but not limited to the ureter, bladder, and urethra, and which are anchored extraluminally by porous biocompatible tissue-bonding material, do not usually transmit intraluminal bacteria to the extraluminal porous biocompatible tissue-bonding material. Nonporous biocompatible alloplast tubes, such as silicone tubes, in chronic contact with urine are subject to coating with urinary mucus, encrustation, and stone formation from the dissolved salts contained in the urine. Periodic low morbidity, low-cost replacement of such tubes is desirable.
The present invention is directed toward making implantable medical devices that make effective use of the tissue-bonding properties of porous biocompatible tissue-bonding material, such as polytetrafluoroethylene, polyurethane or polyester fiber, and that also contain a renewable or replaceable nonporous biocompatible alloplast component which can be periodically replaced. A suitable polyester fiber is sold under the trademark Dacron.RTM..
The present invention is directed toward a modular implantable conduit that will allow replacement of the component most likely to become problematic. This invention will decrease the time, expense, and complexity of surgery required to replace such implants.
The present invention also encompasses a surgical method of implanting the conduit. The present invention envisions that the conduit may be used to transport energy (such as electrical, magnetic, or pneumatic), or fluid (such as urine, blood, glandular fluid, or spinal fluid), into or out of the body. The conduit may also be used to transport energy or fluid within or between viscera and other organs. The conduit may contain one or multiple additional components such as reservoirs or sampling chambers. It is also envisioned that the conduit may be used for sampling, evacuating, or adding to body fluids and/or tissues. The present invention may also be a component in a modular system wherein the conduit is attached to a tissue bonding cystostomy tube.